Side curtain air-bag

ABSTRACT

In at least one embodiment of the present invention, an inflatable curtain for a motor vehicle is provided. The inflatable curtain is formed of layers of fabric and is deployable from a rolled state forming a roll to an inflated state. The air-bag comprises part of the air-bag that forms the upper-most edge of the air-bag when the air-bag is in the inflated state extending downwardly from the roll to lie proximate a side part of the motor vehicle on which the air-bag is to be mounted. At least a portion of the roll is positioned above the upper-most edge in the rolled state and is driven downward below the upper-most edge during deployment to the inflated state. The air-bag further provides a gas flow duct. When the air-bag is in the rolled state, the gas flow duct is provided at the top part of the roll.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and is a continuation application ofU.S. patent application Ser. No. 10/577,810, filed Apr. 28, 2006, nowU.S. Pat. No. 7,527,287, entitled “SIDE CURTAIN AIR-BAG”, which ishereby incorporated herein by reference. U.S. patent application Ser.No. 10/577,810 claims priority to and all benefits of Great Britainpatent application number 0325540.3, filed Oct. 31, 2003 andPCT/EP2004/012155, filed Oct. 27, 2004.

FIELD OF THE INVENTION

The present invention relates to an air-bag arrangement, and moreparticularly relates to an air-bag arrangement in the form of aninflatable curtain.

BACKGROUND OF THE INVENTION

It is known to provide an air-bag in the form of a so-called “inflatablecurtain”. An air-bag of this type is usually mounted in the roof of amotor vehicle and, on inflation, is intended to lie adjacent the sidewindows of the vehicle, thus constituting a “side curtain” in order toprovide protection for the head of an occupant of the vehicle. A sidecurtain of this type may be of substantial advantage for a vehicleoccupant in the event of a side impact or roll-over situation.

Many proposals have been made in connection with such inflatablecurtains.

WO 02/085674 A2 shows an inflatable curtain and shows a specific methodfor folding the curtain. The curtain is folded by using a rollingtechnique which rolls the curtain about an axis which, when mounted inthe vehicle, is substantially horizontal, a terminal part of the curtainthen being folded to extend generally upwardly above the roll. Thefolded curtain is mounted in position by using this upwardly directedportion. On deployment of the air-bag, the air-bag effectively unrollsto lie adjacent a side window of the vehicle.

The disadvantage with the arrangement of WO 02/085674 A2 is that itinvolves a rolling technique and also a folding technique, meaning thatassembly apparatus must be provided to effect the rolling operation andseparate apparatus must be provided to effect the folding operation.

SUMMARY OF THE INVENTION

The present invention seeks to provide an improved air-bag arrangement.According to the present invention, there is provided an air-bagarrangement, in the form of an inflatable curtain, the inflatablecurtain being rolled to form a roll, part of the inflatable curtain thatis to form the upper-most edge of the inflatable curtain when inflatedextending downwardly from the roll to lie adjacent a side part of amotor vehicle on which the inflatable curtain is to be mounted.

Preferably, the part of the inflatable curtain extending downwardly fromthe roll is a substantially uninflatable region provided with one ormore mounting formations. Advantageously, the mounting formationscomprise a plurality of mounting tabs to be connected to mounting lugs.Conveniently, the mounting formations comprise a plurality of mountingapertures to engage bolts, “Christmas tree” snap connectors or the like.Preferably, the air-bag is associated with a mounting bracket.Advantageously, the mounting bracket incorporates an open topped channeldimensioned to receive part of the downwardly-extending part of theair-bag. Conveniently, the side-walls of the channel are provided withco-aligned apertures to be co-aligned with the mounting apertures formedin the air-bag, to enable mounting elements in the form of bolts,“Christmas tree” snap connectors or the like to pass through theco-aligned apertures to mount the bracket and thus the inflatablecurtain to a motor vehicle. Preferably, the bracket incorporates aplurality of hooks. Advantageously, the hooks are provided at a positionabove the open-topped channel to engage apertures provided in aside-wall of a motor vehicle. Conveniently, the bracket includes asupporting platform to support the rolled air-bag. Preferably, therolled air-bag is contained within a protective cover. Advantageously,the protective cover comprises a sleeve provided with a breakable seam.

Conveniently, the air-bag is rolled towards the outboard side of theair-bag.

Preferably, the air-bag incorporates a gas flow duct, the gas flow duct,when the air-bag is rolled, being provided at the top part of the roll.

Advantageously, the one or more mounting formation is located at aposition which is not above the upper-most part of the air-bag roll, andmay be located completely below the roll.

DESCRIPTION OF THE DRAWINGS

In order that the invention may already be understood, and so thatfurther features thereof may be appreciated, embodiments of theinvention will now be described, by way of example, with reference tothe accompanying drawings in which:

FIG. 1 is a diagrammatic sectional view of part of an air-bagarrangement in accordance with the invention,

FIG. 2 is a view corresponding to FIG. 1 showing a modified embodimentof the invention, and

FIG. 3 is a view corresponding to FIGS. 1 and 2 showing a furthermodified embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Here it is to be understood that a typical inflatable curtain, as ingeneral use, is provided, adjacent its upper-most edge, with a pluralityof mounting lugs or equivalent fixing devices to secure the upper edgeof the inflatable curtain to the part of the roof of a motor vehiclewhich extends above the side door openings and/or side windows of thevehicle. The inflatable curtain may extend the whole length of thevehicle cabin or only part of the length of the vehicle cabin.

Typically, adjacent the upper edge of the inflatable curtain, a gas flowduct is provided which extends across the whole length of the inflatablecurtain. Below the gas flow duct are a plurality of inflatable cells orchambers, and some of the inflatable cells or chambers may be separatedby uninflatable regions.

There are many different detailed designs of inflatable curtain, and thepresent invention is not related to any specific design.

FIG. 1 illustrates an air-bag 1 in the form of an inflatable curtain 1which is shown in a rolled condition. The edge 2 of the inflatablecurtain air-bag 1 which forms the upper-most or top edge when theinflatable curtain is inflated is shown emerging from a generallyspiral-wound roll 3, with the edge 2 being directed so as to extenddownwardly. Adjacent the edge 2 the air-bag 1 is provided with amounting formation in the form of a tab 4. The rolled air-bag 1 is shownimmediately adjacent part S of the side of a motor vehicle, and amounting lug L is shown provided on the side part S of the motor vehiclefor co-operation with the mounting tab 4 to secure the air-bag 1 to thevehicle.

The part of the side curtain air-bag 1 extending upwardly from the edge2 and adjacent the mounting tab 4 forms an uninflatable region 5.Immediately adjacent the uninflatable region 5 is a region of theinflatable curtain that forms a transversely extending gas flow duct 6.The gas flow duct 6 is defined between two sheets of fabric that havebeen connected together to form the inflatable curtain. In analternative embodiment, the gas flow duct may be a separate tube, whichis separate from the main part of the inflatable curtain. The tube maybe of plastic, textile or metal. The sheets of fabric may be sewntogether but typically are formed simultaneously using a one-pieceweaving process which is known per se. The two sheets of fabric areshown woven together to form a seam 7 that defines the lower-most edgeof the gas flow duct 6. It is to be observed that the gas flow duct 6extends across the top most part of the roll 3. The roll 3 continuesconcentrically inwards, the lower-most or bottom edge 8 of theinflatable curtain being located at the centre of the roll. It is to beunderstood that the region between the seam 7 and the lower-most edge 8is provided with the above-mentioned cells or chambers. The cells orchambers, when inflated, constitute a passenger protecting area.

Here it is to be understood that the roll 3, in this embodiment, hasbeen formed by rolling the lower-most edge of the inflatable curtaintowards the side of the inflatable curtain air-bag 1 which, when theinflatable curtain is inflated, constitutes the “outboard” side of theinflatable curtain. The rolling may be accomplished using any convenientform of rolling apparatus.

It is to be appreciated that the inflatable curtain air-bag 1 of FIG. 1will be contained within an appropriate package, such as a fabric sleeveor a housing surrounding the roll 3, but the package is not shown atthis stage for the sake of clarity.

In the event that the inflatable curtain air-bag 1 is to be inflated, inan accident situation, gas is initially supplied to the gas flow duct 6from a gas generator (not shown). The gas flow duct 6 thus becomesinflated, at least along part of the length of the gas flow duct. Sincethe gas flow duct extends across the top of the roll 3, inflation of thegas flow duct will tend to drive the rest of the roll 3 downwardly.Consequently a downward motion is imparted to the main part of theinflatable curtain air-bag 1. This facilitates the ready inflation ofthe air-bag 1 so that it occupies a fully deployed state within a veryfew milliseconds of deployment being instigated.

As the inflatable curtain air-bag 1 becomes deployed, so the roll 3 willunroll. Because the roll has been rolled “towards” the outboard sides ofthe inflatable curtain, the inflatable curtain air-bag 1 will unroll insuch a way that the main body of the roll tends to be driven towards theadjacent window or side part S of the vehicle. The inflating sidecurtain air-bag 1 will therefore tend to position itself between thehead of a seat occupant within the vehicle and the adjacent side of thevehicle, even if the head of the occupant is resting lightly against thewindow or sides of the vehicle, for example, if the seat occupant issleeping. It is to be understood that it would be possible, if theair-bag 1 unrolled in the opposite sense, for the air-bag to ride overthe head of a vehicle occupant if the head of the occupant were lyingadjacent the window, with the head of the occupant thus becoming trappedbetween the air-bag and the window. This is clearly undesirable.

FIG. 1 illustrates a very simple embodiment of the invention. FIG. 2illustrates a rather more detailed embodiment of the invention. In thisembodiment, the roll 3 described above has been compressed so as to havean oval or more rectangular cross-sectional shape, so that the roll 3 isless obtrusive in the roof-lining of the vehicle. The roll has beensurrounded by a textile cover 9 in the form of a sleeve, which has abreakable tape seam 10. The tape seam 10 is intended to rupture oninstigation of deployment of the air-bag. Alternatively the textilecover could have a tear line, such as a perforation, or some other lineof mechanical weakness.

In this embodiment of the invention the uninflatable region 5 adjacentthe upper-most edge 2 of the inflatable curtain air-bag 1 is providedwith a mounting aperture 11, and the free edge 2 is received within achannel or slot 12 formed in a mounting bracket 13. The slot 12 is anupwardly open channel. The mounting bracket 13 incorporates a supportingplatform portion 14 which extends beneath the roll 3 to support theroll, and a mounting bolt 15 is provided which extends throughco-aligned apertures formed in opposite sides of the channel 12 andwhich also passes through the mounting aperture 11 formed in theuninflatable region 5 of the inflatable curtain. The bolt 15 may bereceived within an appropriate mount 16 which may be threaded in theside part S of the vehicle, to secure the air-bag 1 to the motorvehicle.

It is therefore to be noted that in both the embodiment of FIG. 1 andthe embodiment of FIG. 2 the air-bag 1 is mounted in position within thevehicle by co-operating mounting formations which are located separatelybeneath the main body of the roll 3.

FIG. 3 illustrates an embodiment which is similar to that of FIG. 2,save that the mounting bracket 13A comprises an additional upwardlyextending finger or flange 17 which extends upwardly from the channel 12to a position slightly above the mid-point of the roll 3 on the outboardside of the roll 3. The finger 17 terminates with a downwardly-turnedhook 18 shown engaged with an aperture 19 formed in the side part S ofthe vehicle. In the embodiment of FIG. 3 the bolt 15 has been replacedby a “Christmas tree”-type snap connector 20.

It is to be appreciated that in mounting the embodiment of FIG. 3 inposition in a motor vehicle, initially the hook 18 will be engaged withthe aperture 19 and subsequently the Christmas tree fastener 20 will beengaged with the co-operating mounting 16 formed in the side part S ofthe vehicle.

Of course, in each embodiment described above, a plurality of mountingconfigurations will be provided spaced along the length of theinflatable curtain air-bag 1. Thus in the embodiment of FIG. 1 therewill be a plurality of attachment tabs 4 and co-operating attachmentlugs L, e.g., second mounting lug L and second mounting tab 14 indicatedby dashed lines (schematic and for illustrative purposes only). In theembodiment of FIG. 2 there will be a plurality of bolts 15 and in theembodiment of FIG. 3 there will be a plurality of Christmas tree snapconnectors 20 and a plurality of hooks 18.

In each of the described embodiments, the roll 3 is mounted in positionin the motor vehicle by means of one or more mounting arrangements, themounting arrangements all being located at a level which is not abovethe top-most part 22 of the roll 3. In the preferred embodiments, themounting arrangements include at least one mounting arrangement locatedbeneath the lower-most part 24 of the roll 3.

In the described preferred embodiments of the invention the roll 3 islocated above the mounting arrangement. This has the advantage thatthere is usually more space available in an upper portion of the roofframe, rather than the lower portion, and thus at least most of thepackaged inflatable curtain air-bag 1 is located in part of the roofwhere there is ample space to accommodate it.

It is to be understood that the invention provides the advantage thatthe inflatable curtain air-bag 1 can be simply rolled and packaged, andthere is therefore no requirement for a folding apparatus to be providedin addition to the rolling apparatus to facilitate packaging of theinflatable curtain.

While the above description constitutes the preferred embodiment of thepresent invention, it will be appreciated that the invention issusceptible to modification, variation, and change without departingfrom the proper scope and fair meaning of the accompanying claims.

1. An inflatable curtain for a motor vehicle formed of layers of fabricand being deployable from a rolled state forming a roll to an inflatedstate, the air-bag comprising part of the air-bag that forms theupper-most edge of the air-bag when the air-bag is in the inflated stateextending downwardly from the roll to lie proximate a side part of themotor vehicle on which the air-bag is to be mounted, wherein at least aportion of the roll is positioned above the upper-most edge in therolled state and is driven downward below the upper-most edge duringdeployment to the inflated state, wherein the air-bag further provides agas flow duct, and when the air-bag is in the rolled state the gas flowduct extends along a top-most part of the roll such that duringdeployment the gas flow duct initially inflates driving a remainingportion of the roll downward to facilitate deployment to the inflatedstate, wherein the air-bag is rolled to form the rolled state in adirection towards the outboard side of the air-bag, wherein in therolled state the upper-most edge extends downwardly from the rollwithout having a fold formed therebetween, and at least an upper halfportion of the roll is positioned above the upper-most edge.
 2. Anair-bag according to claim 1 wherein the upper-most edge that isdownwardly extending is a substantially uninflatable region of theair-bag provided with one or more mounting formations.
 3. An air-bagaccording to claim 1 wherein the air-bag further comprises a mountingbracket.
 4. An air-bag according to claim 1 wherein the air-bag in therolled state is contained within a protective cover.